Rotary pump



lume i2, E923.

W. L. RUTTLEDGE Rommfl PUMP Filed 0013.l 1l 1920 Patented June l2, i923.,

i, sans 'ad G WILLIAM L. RUTTLEDGE, OF DETROIT, MICHIGAN, ASSIGNOR T0 ROTO PUMP MFG. CO., OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

v ROTARY :einen Application filed October 11, 1920.

' To all whom t may concern.'

Be it known that I, IVILLIAM L. Iturr- LEDGE, a subject of the King of Great Britain and Ireland, residinfr at Detroit, in the county of Wayne and tate of Michigan, have invented certain new and useful Improveniente in Rotary Pumps, of which the following is a specification, reference being had therein to the accompanying drawings.

rI`he invention relates to rotary pumps and has for one of its objects the provision of a simple packing for sealing the joint between the blade of the valve and the plston. Another object of the invention is to form the inner surface of the pump casing over which the valves ride in such a manner that the proper extension chamber .is provided, and at the same time all objectionable raises or depressions in the surface are avoided. Further objects reside in the nvel features of construction and combinations and arrangements of parts as more fully set forth.

In the drawings:

Figure 1 is a sectional elevation of a rotary pump embodying my invention;

Figure 2 is a perspective view of a valve;

Figure 3 is a central section therethrough;

Figure 4c is a diagram of the arch curvatures of the casing cavity.

1 is the rotary pump casing comprising the cylinder 2 and the parallel plates 3 at opposite ends thereof. i and 5 are respectively the inlet and outlet passageways in the casing which communicate with the cavity within the cylinder 2 by means of the openings 6 and 7 respectively in the end plates 3. 8 is the rotary shaft upon which is nonrotatably mounted the piston or rotor 9 which is provided with the equidistant pockets 10 in its periphery adapted to receive the valves or buckets 11. rIhese valves have the furcations 12 embracing suitable projections upon the piston and extending into its pockets and are pivotally secured thereto as at 13. The valves also have blades 14 at their free ends, the outer faces 15 of which are concentric with respect to the pivots as are also the end faces 16 of the pockets to permit of the blades being movable thereover.

For the purpose of sealing the joint between these concentric faces 15 and 16, there is the packing strin 17 extending longitudinally 0f a channel in the outer face of each serial no. 416,129.

blade leland throughout its entire length. F or maintaining this packing strip in contact with the end face 16 ofy each pocket, suitable passagew'ays or bores 18 are formed extending through each blade and communicatingwith the bottom of the channel. These passageways permit of pressure being exerted by the fluid being pumped upon the bottoms of the packing strips to force their outer faces into engagement with the end faces of the pockets. Suitable means such as the pin 19 slidably extend through the packing strips and are secured to the blades for preventing the packing strips from becoming longitudinally displaced.

As shown in Figure 3 particularly7 the arch curvatures of the cylinder cavity are formed as follows: 20 is the axis of the shaft 8, and 21-22 is an arc of 60 formed about the point 20 and having substantially the radius of the piston 9. The radial distance 23-24 is the extension of the cylinder cavity and arcs 21-24l and 22-24 connect tangentially into the ends of the arc 21-22 to the point 24. Each of these arcs are similarly formed and therefore but one will be described, namely, arc 21*24. By drawing the line 25-26 perpendicularly to and bisecting the chord 21-24 and by continuing the radius line 21-20, the point of intersection of these lines, as 27, is found which is the center about which the arc 21-2Ll is described. By maintainingthe length of the extension 2324l within approximately 25% of the length of the radius of the piston 9, the arcs 21-24 and 22-24 will meet to form a substantially continuous curve having no objectionable raise or depression for prac tical operation of the pump. The ports i and 5 of the casing begin at the points 21 and 22 and extend around the arcs 21-24 and 22-211 through an angle of 90 each.

From the above description it will be readily seen that I have provided a cylinder, the inner wall of which is formed of simple curves which are easy to machine and which combined form in effect a substantially continuous curve having no raises or depressions therein and consequently permit of the free movement of the valves thereover so that wear of both the valves and cylinder wall is reduced to the minimum.

What I claim as my invention is:

1. Ina rotary pump, the combination with a cylinder, of a piston therein, and a valve yvvith a Wall of said cylinder, the inner surface of said cylinder being composedof an arc having a radius substantially equal to that of said piston and apair of equal arcs vof greater radius and connecting tangenytially into sald first-mentioned arc, and ports in said casing extending from the ends ofsaid first-mentioned arc and connecting into said pair of arcs. p n

' 3. In a rotary pump, the combination .With a casingl including a cylinder, of a piston therein, a valve upon said piston engageable with a Wall ofsaid cylinder, the inner surface of said cylinder. being composed of an are of approximately 60 and having a v' radius substantially equal to that of said piston andl a pair of equal arcs of greater radius and connecting tangentially into said first-mentioned arc at opposite ends thereof, and ports in said casing extending from the opposite ends of said first-mentioned are and connecting into said pair of arcs, said ports being included Wit-hin arcs of approxii mately 90. Y

4:, In a rotary pump, the combination With a casing including a cylinder, of apiston therein, a valve upon said piston engageable with the inner Wall of said cylinder, said Wall comprising. an arcvof approximately 60, and a pair of equal arcs of approximately ,150 connecting tangentially I into said first-mentioned arc at opposite ends thereof, said first-mentioned are having a radius substantiallyy equal to thatl of said piston, and .each of said pair of arcs having a radius greaterthan that of said first-mentioned are but Within approximately 125 per cent of the radius of said piston. A

In testimony whereof I affix my signature.

WILLIAM I). RUTTLEDGE. 

